Digital alloy based back barrier for p-channel nitride transistors

Abstract

A III-nitride power handling device and the process of making the III-nitride power handling device are disclosed that use digital alloys as back barrier layer to mitigate the strain due to lattice mismatch between the channel layer and the back barrier layer and to provide increased channel conductivity. An embodiment discloses a GaN transistor using a superlattice binary digital alloy as back barrier comprising alternative layers of AlN and GaN. Other embodiments include using superlattice structures with layers of GaN and AlGaN as well as structures using AlGaN / AlGaN stackups that have different Aluminum concentrations. The disclosed device has substantially increased channel conductivity compared to traditional analog alloy back barrier devices.

Description

TECHNICAL FIELD[0001]The present disclosure is directed in general to the area of III-Nitride transistors and in particular to the design and fabrication of P-Channel GaN Transistors.BACKGROUND OF THE DISCLOSURE[0002]GaN power integrated circuits (IC) have the potential of dramatically reducing the size and weight of power electronic systems, thereby substantially reducing the cost of power electronic devices. P-channel GaN-transistor is a critical component for making GaN power ICs. Such power electronic systems are widely needed in electric / hybrid vehicles, more-electric aircrafts, as well as many consumer electronic products.[0003]A variety of GaN transistors are known and they include P-Channel transistors in conjunction with N-Channel transistors using an analog alloy to improve conductivity. The use of a tertiary alloy such as AlGaN (Aluminum-Gallium-Nitride) is often referred to as analog alloy in the art. To increase power handling capacity of GaN transistors, several techni...

AI Technical Summary

Benefits of technology

The patent is about a design for a digital alloy that reduces strain caused by a mismatch of lattices between layers. The design can use binary or ternary digital alloys, and can help improve performance and reliability of electronic devices that use these alloys.

Problems solved by technology

However thick analog AlGaN with high Al content cannot be grown on GaN buffer due to the lattice mismatch.

This is a fundamental limit of using analog AlGaN alloys as the back-barrier.

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